[ECP-9133][ECP-9225] Unable to place an order with discount code using Klarna

[piotrmatras]

Describe the bug
Unable to place an order with discount code using Klarna payment method. I'm receiving the following error from payment gateway:
Internal error: Result from Open Invoice service does not contain a redirect URL
Error code: 903

Example quote details:
Subtotal: 79,95€
Discount: -8,00€
Shipping cost: 4,80€
Tax: 13,53€ (19% German tax)
Grand total: 76,65€

Request payload (see attached screen below):
amount: 7665 [ok]
lineItems:

• product: 7022
• shipping: 480
  SUM: 7502 [wrong]

To Reproduce
Steps to reproduce the behavior:

1. Add product to cart
2. Apply a discount code with -10% discount
3. Go to checkout and try to place an order using Klarna method

Expected behavior
I'm able to place an order including discount code.

Magento version
2.4.6

Plugin version
9.4.0, 9.4.1

Screenshots

[RokPopov]

Hi @piotrmatras, we tried to reproduce the issue with the default tax calculation settings, it doesn't cause an issue. Would you be able to share all of the settings from the following page:

• Stores >> Configuration >> Sales >> Tax

Could you please also clarify whether you have multicurrency setup and if you are also applying 10% discount on shipping?

Thank you in advance!

[piotrmatras]

HI @RokPopov
See screenshots below

• allowed currency: EUR
• 10% discount only for products

[candemiralp]

Hello @piotrmatras,

Thank you for providing the information above. With the configuration values that you have provided, we've successfully reproduced the issue. It looks like line item calculator has a bug if Apply customer tax is set to Before.

We've created an internal ticket to fix it.

Best regards,
Can